Warning signs call attention to unexpected conditions on or adjacent to a highway, street, or private roads open to public travel and to situations that might not be readily apparent to road users. Warning signs alert road users to conditions that might call for a reduction of speed, an action in the interest of safety, or actions that promote efficient traffic operations. The use of warning signs is based on an engineering study or judgment, and unless otherwise noted, are generally diamond-shaped and must have a black legend and border on a yellow background. Looking for something you don't see here? Contact Us and we'll be happy to assist you.